knudsen@ihnss.UUCP (05/25/83)
I can't explain the problem Dan Glasser is having with his CG115 (a terminal can drive it but the LSI11 can't). However, as concerns the handshaking: The printer, if it's like any other Radio Shack Coco-oriented peripherals, does generate a reverse handshake which should be fed into the Clear-to-Send on your LSI-11 (hey! maybe that's why she doesn't work). Or maybe into the Data Terminal Ready pin, in which case you should feed your Request-to-Send back into Clear-to-Send (pin 4 to 6). One thing you should beware of, if you try to figure out the CG115's pinout based on the Color Computer cable -- for unknown reasons, the Coco must take that handshake in on its Receive Data pin, NOT its Carrier Detect (or DSR, or whatver) "status" pin. I don't think that affects you here. PS--in 1st para I meant Data Set Ready, I think-- depends on how you assign the roles of "modem" and "terminal". I think you know what I mean. Concerning voltages -- maybe so. Measure what your LSI11 puts out for hi & lo. the Coco generates nearly +-12 volts, so the CG115 might be picky, with lots of hysteresis on its Receive Data. Do you have any instruments to tell whether your LSI11 actually sens anything to the printer? I.e., is your interface hung or does the printer ignore the data? good luck mike k